1. Field of the Invention
The present invention relates to a method of producing adamantyl acrylate compounds which attract attention as the raw materials of resists for KrF, ArF, or F2 excimer laser, resists for X ray, electron beam or extreme ultraviolet (EUV), high performance polymers, etc.
2. Description of the Prior Art
In the general production of 2-alkyl-2-adamantyl (meth)acrylates from a 2-adamantanone derivative corresponding to their ester moiety, the 2-adamantanone derivative is converted into a 2-alkyl-2-adamantanol derivative and then the 2-alkyl-2-adamantanol derivative is allowed to react with (meth)acryloyl halide, etc.
K. Nozaki et al., Jpn. J. Appl. Phys. 35, 528 (1996) discloses the production of 2-methyl-2-adamantyl methacrylate by the esterification between 2-methyl-2-adamantanol and methacryloyl chloride. Japanese Patent Application Laid-Open No. 2000-229911 discloses the production of 2-alkyl-2-adamantyl (meth)acrylate by the reaction of a corresponding 2-alkyl-2-adamantanol derivative and (meth)acryloyl chloride. In the method disclosed in Japanese Patent Application Laid-Open No. 2000-309558, a corresponding 2-alkyl-2-adamantanol derivative or its metal salt is reacted with (meth)acryloyl halide.
Japanese Patent Application Laid-Open No. 10-182552 discloses the production method of a tertiary alcohol ester of carboxylic acid (for example, adamantyl ester of carboxylic acid) by reacting a ketone compound (for example, 2-adamantanone) with a carboxylic acid halide in the presence of an organometallic compound without separating and purifying the tertiary alcohol derived from the ketone compound.
In the methods disclosed in WO 01/87817 and Japanese Patent Application Laid-Open No. 2003-73334, 2-adamantanone and an alkyl halide dissolved or dispersed in a solvent are reacted in the presence of lithium metal into lithium 2-alkyl-2-adamantanolate that is then reacted with methacryloyl halide, thereby producing a 2-alkyl-2-adamantyl methacrylate.
These methods, however, involve drawbacks of using the expensive (meth)acryloyl halide as the esterifying agent which is difficult to handle and generates a large amount of by-products difficult to remove. The use of the (meth)acryloyl halide by-produces alkyladamantyl halide that generates acid during the purification by distillation to decompose the aimed 2-alkyl-2-adamantyl (meth)acrylate and significantly reduce its yield.
Japanese Patent Application Laid-Open No. 2001-97924 proposes a method for preventing the reduction of yield, wherein a mixture of alkyladamantyl halide and a 2-alkyl-2-adamantyl (meth)acrylate is contacted with an alkali compound to convert the alkyladamantyl halide into a compound not generating acid during the purification by distillation. In addition, Japanese Patent Application Laid-Open No. 2000-229911 proposes a method for producing a 2-alkyl-2-adamantyl (meth)acrylate in high yields by using acid chloride prepared by the reaction of benzoyl chloride or phosphorus trichloride with (meth)acrylic acid. However, since the use of acid halide requires a specific means, it has been demanded to develop an industrially easy-to-practice method of producing the adamantyl acrylate compound in high yields without using acid halide.
In the method of Japanese Patent Application Laid-Open No. 2002-241342, a 2-adamantanone compound is reacted with a (meth)acrylic ester or a (meth)acrylic anhydride in the presence of an organometallic compound. In this method, the adamantyl (meth)acrylate compound is produced in a sufficiently high yield. However, to produce the aimed adamantyl acrylate compound, it is needed to prepare an organometallic agent such as alkyllithium and alkylmagnesium halide in advance, making the production process long. Some of the organometallic agents result in poor yields and some are poor in storing stability. This makes the industrial production thereof difficult in some cases.